Gamalama

Indonesia

0.8°N, 127.33°E; summit elev. 1715 m

All times are local (unless otherwise noted)

On 17, 23, and 24 May seismic tremor was recorded for periods of 3-8 minutes. Deeper earthquakes were recorded at a rate of 13/day during late May. White fume was consistently present above the crater, rising more than 400 m above the summit. A plume has probably been emitted intermittently since the 12 February explosive eruption.

Geologic Background. Gamalama is a near-conical stratovolcano that comprises the entire island of Ternate off the western coast of Halmahera, and is one of Indonesia's most active volcanoes. The island was a major regional center in the Portuguese and Dutch spice trade for several centuries, which contributed to the thorough documentation of Gamalama's historical activity. Three cones, progressively younger to the north, form the summit. Several maars and vents define a rift zone, parallel to the Halmahera island arc, that cuts the volcano. Eruptions, recorded frequently since the 16th century, typically originated from the summit craters, although flank eruptions have occurred in 1763, 1770, 1775, and 1962-63.